Front body structure for vehicle bodies

ABSTRACT

A light-weighted and high rigidity front body structure for vehicle bodies is disclosed. The front body structure comprises a transverse dash panel member extending over and welded to a dash panel or another member close to the dash panel and a transverse instrument panel member extending in the close vicinity of the dash panel. The instrument panel member, which is preferably formed from a pipe by hydro-forming, has opposite end portions welded to opposite side panels of the front body, respectively, and a generally U-shaped central portion opening upward and welded to a floor panel at a bottom thereof.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to a body structure for vehiclebodies, and in particular to a front body structure forming a frontportion of a passenger compartment for automobiles that are one oftypical vehicles.

[0003] 2. Description of Related Art

[0004] Recently various kinds of so-called hydro-forming has beenproposed as one of forming methods of forming metal members in theautomobile industries. Hydro-forming is a molding or forming method toform a high tensile strength steel pipe to a given shape. The pipemember is placed in a die cavity and filled with a fluid such as waterand oil. The pipe member is expanded by pressurizing the fluid until thepipe member is deformed to an external shape reflecting the contour ofthe die cavity. Such hydro-forming is known from, for example, Japanesea Unexamined Patent Publications Nos. 10-218017 and 11-235963 as appliedto forming a reinforcement having a rectangular closed cross-section fora side shill or a center pillar of a vehicle body. In the hydro-forming,a pipe member for a reinforcement of a side shill is placed betweenupper and lower dies between which a cavity having a contour identicalto an external shape of the reinforcement is formed, and then,pressurizing fluid is introduced into the pipe member so as to expandthe pipe member until the pipe member is deformed to a shape reflectingthe given contour of the cavity. The reinforcement thus formed is put ina follow side frame of a vehicle body and welded to the side frame.According to another example, a reinforcement having a rectangularclosed cross-section, which is used to reinforce a center pillarextending downward from a roof side rail, is formed from a pipe memberby the hydro-forming. The reinforcement is put in an internal space ofthe center pillar comprising a center pillar outer and a center pillarouter.

[0005] The hydro-forming can provides a pipe member with any externalshape according to the given contour of the die cavity. By using thistechnology it becomes possible to obtain more lightened but more rigidstructural members having various desired shapes as compared withsimilar members that are made by welding a plurality of stamped steelplates.

[0006] Generally a cowl structure located in front of a cabin orpassenger compartment of an automobile that is a typical one of vehiclesis an important structural part for safety because the cowl structure isnot only contributory to ensure a body rigidity but also works as a basewhich mounts thereon a steering shaft and an air-bag that requirehigh-accuracy and delicate adjustment in fitting position. However, thecowl structure needs a large number of parts that are usuallycomplicated in shape, so that many restraints are put on designing andassembling the parts. Although, it is desirable to form the cowlstructure from a reduced number of parts formed by the hydro-forming inlight of simplifying assembling the parts to a cowl structure,nevertheless, a more reliable structure is needed because the cowlstructure is of very importance in the terms of sufficient rigidity andsafety of the vehicle body.

SUMMARY OF THE INVENTION

[0007] An object of the present invention is to provide a front bodystructure for vehicles which provides the front body with light weightand high rigidity.

[0008] The above object of the present invention is accomplished by afront body structure that comprises a dash panel separating a cabin orpassenger compartment from the remaining part of a vehicle body, a dashpanel member extending in a transverse direction of the vehicle bodywhich is welded to the dash panel or another member disposed in theclose vicinity of the dash panel, and an instrument panel memberextending in the transverse direction in the close vicinity of the dashpanel and supported at opposite ends thereof by side panels. The dashpanel member and/or the instrument panel member are formed from a hollowpipe formed by hydro-forming. Each of the dash panel member and theinstrument panel member has opposite ends welded to the side panels ofthe vehicle body, respectively.

[0009] According to the preferred embodiment of the present invention, apipe member as the instrument panel member has opposite ends welded tothe side panels having door openings, respectively, and a generallyU-shaped central portion opening upward and welded to a floor panel at abottom thereof.

[0010] According to another preferred embodiment of the presentinvention, a pipe member formed as the dash panel member has oppositeend portions, each of which extends downward on the inner wall of theside panel along the door opening so that the end of the dash panelmember is welded to the dash panel member in the close vicinity of theside panel, and a pipe member formed as the instrument panel member hasopposite ends welded to the dash panel member in the close vicinity ofthe side panels and a generally U-shape central portion opening upwardand welded to the floor panel at a bottom thereof.

[0011] The instrument panel member may be provided with brackets weldedthereto for mounting a steering shaft and an air-bag on a passengersseat side on an intermediate portion of the instrument panel memberbetween the generally U-shape central portion and one of the oppositeends of the instrument panel member on the passenger seat side. Further,the dash panel member may be provided with a cowl member extending inthe transverse direction of the vehicle body and having a closedcross-section.

[0012] The front body structure of the present invention, including atleast one of the dash panel member and the instrument panel member whichare formed from a pipe member by hydro-forming, is comprised by andecreased number of parts by spot-welding them at a reduced number ofpoints. This provides the front body with lighter weight and higherstructural rigidity as compared with prior art front bodies. Inconsequent, the front body structure realizes firm and reliableinstallation of brackets for mounting steering shaft and an air-bag toone of the intermediate portions of the instrument panel member.

[0013] The front body structure of the present invention, including thedash panel member formed from a pipe member which has the end portionextending downward along the door opening of the side panels and weldedto the side sill, provides a wide area for welding. This wide area ofwelding provides the front body with high structural rigidity.

[0014] The front body structure of the present invention, including thedash panel member and the instrument panel member formed from pipemembers, respectively, which are welded to the inner wall of the vehiclebody, improves the structural rigidity of the vehicle body and providesa light weighted front body due to a reduced number of parts.

[0015] Furthermore, the front body structure of the present invention,including the dash panel member formed from a pipe member ensures asufficient structural rigidity of the front body. This increases thedegree of designing a cowl structure because the dash panel memberformed from a pipe member provides the front body with a high rigidity.

BRIEF DESCRIPTION OF DRAWINGS

[0016] The foregoing and other objects and features of the presentinvention will become more apparent from the following description inconnection with the preferred embodiments thereof when considering inconjunction with the accompanying drawings, in which:

[0017] FIG.1 is a perspective view showing a front body structure of acabin or passenger compartment of a vehicle body at a passenger seatside in accordance with a preferred embodiment of the present invention;

[0018]FIG. 2 is front view of the front body structure;

[0019]FIG. 3 is a cross-sectional view taken along line III-III of FIG.2;

[0020]FIG. 4 is a cross-sectional view taken along line IV-IV of FIG. 2;

[0021]FIG. 5 is a cross-sectional view taken along line III-III of FIG.2, which shows a cowl different from a cowl shown in FIGS. 3 and 4;

[0022]FIG. 6 is an explanatory view showing a process of welding a dashpanel member to a side panel by spot-welding;

[0023]FIG. 7 is an explanatory view illustrating a hydro-forming machinewhich can be applied to forming a structural member such as a dash panelmember and a instrument panel member;

[0024]FIG. 8 is an illustration explaining a process of forming astructural member from a pipe member by hydro-forming; and

[0025]FIG. 9 is a cross sectional view showing an object member deformedin a die cavity by hydro-forming.

DETAILED DESCRIPTION OF THE INVENTION

[0026] Referring to the drawings in detail, and in particular to FIGS. 1and 2 showing a body structure of a front portion of a passengercompartment according to a preferred embodiment of the invention. InFIG. 1 the front body structure is depicted at a side of a passengerseat. In FIG. 2 the front body structure is depicted as viewed from thefront of the vehicle body. Various points of the front body for spotwelding are marked with a cross (X) in FIG. 1 and with a black triangle(□)in FIG. 2.

[0027] A dash panel member 1 that is formed from a pipe member extendsin a transverse direction of the vehicle body (not shown) along and iswelded to an upper portion of a dash panel separating a cabin orpassenger compartment from an engine room. Each of opposite ends of thedash panel member 1 is bent so as to extend rearward along an inner wallof side panels 4 (only one of which is shown) and then downward to aside sill 5 along a rim 4 c forming a door opening in the side panel 4.The dash panel member 1 is spot-welded to the side panel 4 at a numberof appropriate points. This structure in which the dash panel member 1is welded in a wide area to a side structure of the front body includingthe side panel 4 and the side sill 5 leads to improvement of structuralrigidity of the vehicle body. An instrument panel member 2 that isformed from a pipe member extends in the transverse direction and iswelded at opposite ends to the dash panel member 1 in the vicinity ofthe side panels 4. As shown in FIG. 2 the instrument panel member 2 hasa generally U-shaped central portion 2 b opening upward and oppositeside portions 2 a. Each side portion 2 a of the instrument panel member2 is welded to a floor panel 6 at several points. A reinforcement member11 extends in the transverse direction and is welded, or otherwisesecured, to upper end of the U-shaped central portion 2 b as areinforcing bridge.

[0028] This front body structure of the above embodiment reduces thenumber of structural parts and the number of welding points, which leadsto a reduction in body weight and provides a high rigid front body withhigher torsion-resistance as compared to conventional front bodystructures.

[0029] There are provided in the passenger compartment a bracket 7mounting an air-bag (not shown) for a passenger, a bracket 8 securing aninstrument panel (not shown) and a bracket 10 supporting a steeringshaft are secured to the U-shaped central portion 2 b of the instrumentpanel member 2. As the dash panel member 1 and the instrument panelmember 2 have high rigidity as described above, the front body structureprovides the reliable installation of the steering shaft and the air-bagthrough the brackets 7-9 which requires delicate adjustment and highinstalling accuracy. This structure guarantees the safety of the vehiclebody.

[0030] The dash panel member 1 and the instrument panel member 2 areformed from a high tensile strength steel pipe by using a hydro-formingtechnology. A cowl member (not shown in FIG. 1 and FIG. 2) is welded, orotherwise secured, to the dash panel member 1.

[0031] The following description is directed to the front body structureincluding the cowl member with reference to FIGS. 3 and 4 which arecross sectional views taken along lines III-III and IV-IV of the FIG. 2,respectively.

[0032] As shown in FIGS. 3 and 4, the dash panel member 1 is welded, orotherwise secured, to upper part of the dash panel 3. A cowl 21, whichcomprises two parts, namely a cowl upper 21 a and a cowl lower 21 b, iswelded to lower part of the dash panel member 1. The floor panel 6 at afront edge portion thereof is welded, or otherwise secured, to the lowerpart of the dash panel 3. At completion of assembling the vehicle body,a front windshield 23 is installed above the upper portion of the dashpanel 3 through a busc24 disposed therebetween. The U-shaped centralportion 2 b of the instrument panel member 2 is located in the inside ofa center console 25 depicted by a dotted line in FIG. 3. The transverseportion 2 a of the instrument panel member 2 at the side of thepassenger seat is located in the inside of a dashboard 26 depicted by adotted line in FIG. 4.

[0033] The instrument panel member 2 has the U-shaped central portion 2b as described above. The U-shaped central portion 2 b is such as tobecome wider as it comes down toward the floor panel 6. This change inwidth is suitable for having the instrument panel member 2 fixed firmlyto the floor panel 6. Even though the instrument panel member 2 has sucha complicated configuration, it can be made from a single member such asa high tensile strength steel pipe by using hydro-forming.

[0034] The cowl upper 21 a, which is welded to the dash panel member 1,and the cowl lower 21 b are not limited to the cross section shown inFIGS. 3 and 4, but can have a variety of cross sections such as shown inFIG. 5 by way of example.

[0035]FIG. 5 is a cross sectional view taken along line III-III of FIG.2. As shown in FIG. 5, the cowl 21 comprises a cowl upper 21 a and acowl lower 21 b. However, different from the cowl 21 shown in FIG. 3,upper end portion of the dash panel 3 is welded to the cowl lower 21 bin the vicinity of the dash panel member 1. Although, in FIGS. 3 to 5,the cowl upper 21 a at a front end portion is welded to the under sideof the dash panel member 1, the upper cowl 21 a at the front end portionmay be welded to the side of the dash panel member 1. The structuralconfiguration in which the cowl 21 is partly welded to the dash panelmember 1 can take various forms in accordance with body configurationsand/or purposes of vehicles. In any cases, the degree of designing thestructure of a cowl and its associated parts is increased because thedash panel member 1 made of a pipe member provides a simple structureand insures high rigidity of the of the front portion of the cabin.

[0036]FIG. 6 is an explanatory view showing how to weld the dash panelmember 1 to the side panel 4. A spot welding gun 31, specifically one 31a of a welding heads, is inserted into the inside of the side panel 4(which comprises a side panel outer 4 a and a side panel inner 4 b)through an access opening 9 formed in the side panel inner 4 b so as tohold the dash panel member 1 and the side panel inner 4 b between thewelding heads 31 a and 31 b for so-called indirect welding orhollow-body spot welding.

[0037] In this instance, the dash panel member 1 and the instrumentpanel member 2 are formed by hydro-forming as described below withreference to FIGS. 7 to 9.

[0038]FIG. 7 diagrammatically shows a hydro-forming machine 100 which isemployed in the instant embodiment. FIGS. 8 and 9 diagrammatically showa method of hydro-forming the dash panel member 1 and the instrumentpanel member 2. The hydro-forming machine 100 includes an upper half die103 and a lower half die 104, These upper and lower half dies 103 and104 are finished in a given configuration identical to an object member,i.e. the dash panel member 1 or the instrument panel member 2. The upperand lower half dies 103 and 104 are placed under a hydraulic press 102connected to a hydraulic unit 101 through an oil line 105.

[0039] As shown in FIG. 8. a high tensile strength steel pipe 106 isplaced between the upper half die 103 and the lower half die 104. Then,while pressing the upper and lower half dies 103 and 104 against eachother by the hydraulic press 102 (as shown in FIG. 7), an oil is filledin the pipe 106 from the hydraulic unit 101 through the oil line 105 asshaded in FIG. 9 and pressurized by the hydraulic unit 101. As a result,the pipe 106 is expanded until it grows into the shape of die cavityformed between the upper and lower half dies 103 and 104. In thismanner, a given external configuration of the dash panel member 1 or theinstrument panel member 2 is gained.

[0040] Although the present invention has been described with regard topreferred embodiments thereof, various other embodiments and variantsmay occur to those skilled in the art, which are within the scope andspirit of the invention, and such other embodiments and variants areintended to be covered by the following claims.

What is claimed is:
 1. A front body structure for vehicle bodiescomprising: a dash panel separating a passenger compartment fromremaining part of the vehicle body; a dash panel member extending in atransverse direction of the vehicle body, said dash panel member beingsecured to either one of said dash panel and a member disposed in theclose vicinity of said dash panel; a side panel forming each of oppositesides of said passenger compartment, said side panel being formed with adoor opening; and an instrument panel member extending in saidtransverse direction in the close vicinity of said dash panel, saidinstrument panel member having opposite ends welded to said side panels,respectively; wherein said dash panel member is formed from a pipemember.
 2. A front body structure for vehicle bodies comprising: a floorpanel forming a floor of the vehicle body; a dash panel separating apassenger compartment on said floor panel from remaining part of thevehicle body; a dash panel member extending in a transverse direction ofthe vehicle body, said dash panel member being secured to either one ofsaid dash panel and a member disposed in the close vicinity of said dashpanel; a side panel forming each of opposite sides of the vehicle body;and an instrument panel member extending in said transverse direction inthe close vicinity of said dash panel, said instrument panel memberhaving opposite ends welded to said side panels, respectively; whereinsaid instrument panel member is formed from a pipe member such as tohave a generally U-shaped central portion opening upward and secured tosaid floor panel at a bottom thereof.
 3. A front body structure forvehicle bodies as defined in claim 1, wherein said dash panel member hasopposite end portions, each said end portion extending downward alongsaid door opening of said side panels and welded to a side sill.
 4. Afront body structure for vehicle bodies as defined in claim 3, whereinsaid instrument panel member is formed from a pipe member and hasopposite ends welded to said dash panel member near said side panels,respectively, and a generally U-shaped central portion opening upwardand secured to said floor panel at a bottom thereof.
 5. A body structurefor vehicle bodies as defined in claim 2, and further comprising abracket for mounting a steering shaft to said instrument panel member,said bracket being welded to an intermediate portion of said instrumentpanel member between one of said opposite ends and said generallyU-shaped central portion.
 6. A body structure for vehicles as defined inclaim 2, and further comprising a bracket for mounting an air-bag tosaid instrument panel member, said bracket being welded to anintermediate portion of said instrument panel member between one of saidopposite ends and said generally U-shaped central portion.
 7. A frontbody structure for vehicle bodies as defined in claim 1, and furthercomprising a cowl member extended in said transverse direction andhaving a closed cross-section, said cowl member being welded to saiddash panel member.
 8. A front body structure for vehicle bodies asdefined in claim 2, and further comprising a cowl member extended insaid transverse direction and having a closed cross-section, said cowlmember being welded to said dash panel member.
 9. A front body structurefor vehicle bodies as defined in claim 1, wherein said dash panel memberis formed by hydro-forming.
 10. A front body structure for vehiclebodies as defined in claim 1, wherein said instrument panel member isformed by hydro-forming.
 11. A front body structure for vehicle bodiesas defined in claim 2, wherein said dash panel member is formed byhydro-forming.
 12. A front body structure for vehicle bodies as definedin claim 2, wherein said instrument panel member is formed byhydro-forming.